A Romanian man faces a jail sentence after being convicted of skimming 9,000 ATM PINs that could have allowed to him steal over APS3 million ($4.8 million) from British victims.

In a rare open and shut case, 32 year-old Leonid Rotaru was caught on closed-circuit camera fitting a skimming device to an ATM in Bridgwater, Somerset before being arrested when he returned to remove it later on.

The setup recorded the card details when entered through the skimming device while a 'pinhole' camera was used to record the PIN number entered.

Police later retrieved more than 9,000 PIN and card numbers from his address as well as other skimming devices.

The exact sums stolen by Rotaru have not been revealed although police believe he was unlikely to have been acting alone, but as part of a larger and as-yet undetected gang.

"This is usually very organised, you can tell from the quality of the equipment that was attached to the ATM, you can tell from the amount of detail that was found on the computer," said Avon and Somerset Police's Economic Crime Unit's Barry Douglas.

"This was well-organised, well-orchestrated and with good criminal connections."